Rifling guns



"UNITED STATES PATENT OFFICE.

HUGH REILLY, OF BROOKLYN, NEW YORK.

RIFLING GUNS.

SPECIFICATION forming part of Letters Patent No. 245,015, dated August 2, 1881.

Application tiled May 2, 1881.

To all whom it may concern p Beit known that I, HUGH REILLY, of the city of Brooklyn, State of New York, have invented a new and useful lmprovementin Fire- Arms and Ordnance, which is fully set forth in the following specification and accompanying drawing.

The object of my invention is to prevent the escape and consequent loss of any desired portion of the force of the explosion of the charge, and to utilize it, or any desired 'portion of it, for the propulsion of the shot; and I attain this result as follows:

The lands and grooves of the rifling of lirearms and ordnance, as heretofore made, have usually been so cut that the lands did not vary in width from the breech of the gun to the muzzle, nor did the grooves; andwhen shot furnished with sabots to take the ritling are used in guns so rifled the impact of the comparatively soft meta-l of the sabot against the resisting side of the groove of the rifling causes the sabot-metal to be rapidly cut away, so that before the shot has left the muzzle ot' the gun the expanded or enlarged portion of the sabot which took the groove of the rifling has been so much cut away that it no longer fills the groove entirely, but leaves a space through which the gases of combustion escape between the side oi the groove of the riling which is opposite the side against which the 'sabot presses and the expanded portion ofthe sabot which is in the groove of the rifling.

Thus a considerable portion of the force of the charge escapes past the sides of the shot and is blown out of the muzzle of the gun.

My improvement consists in widening the grooves of the rilling in the breech of the gun, where the sabot first takes the rifling by its expansion after the explosion of the charge. By cutting away one Yside of the lands of the riiing the enlargement or widening of the grooves will be seen at a a and the decreased lands at I) b. The edge of the land which resists the straight movement of the sabot is a true spiral from 'breech to muzzle. From the point in the breech where the lands are the narrowest they are gradually widened until they attain their normal width at c c. The distance to which this beveling should extend 4from the breech toward the muzzle and the amount of the lands to be cutaway cannot be (Model.)

given for all guns, because it will vary in guns of different size, in ritling of different pitch, and with shot of different weight. It will also depend largely upon the metal used in the sabots. This can only be ascertained by experimenting with the shot and gun in which the invention is to be used. By this means the wear of the sabot by its excessive grindingor pressure against the side of the groove of the riiling is compensated for by the increase in the width of the lands, which increase constantly reduces the width of the groove, and thus the wear of the sabotis followed up, as it were, by the gradually-wideningland, and there is thus maintained a substantially tight contact between the side ot' thelands and the eX- panded portion of the sabot, and the escape of the gas is prevented.

If it is desired to relieve the gun from the great strain consequent upon conlining allthe force ofthe charge behind the shot, I cutaway portions of the lands, one or more, as desired, as shown at d d; but it is better to cut away more than one, and on opposite sides of the bore, and at about the same distance from the muzzle, so that the flight of the shot may not be affected by the shot being thrown out of center. When the shot has reached the point of this reduction in the width of the lands, as at d d, the gases will escape in a puff through the openings thus furnished, and the strain on the gun will be diminished accordingly. I also usually, to prevent the riiiing from being ragged or torn out at the muzzle, reduce the width of thel lands at the very muzzle, as shown at E E.

It will be particularly noticed that the reductions of the lands in the breech, as at a a, in the length of the gun, as at d d, and at the muzzle are all to be on that side of the lands against which the expanded portion of the sabot presses by reason ofthe twist of the riiling, because the sabot would probably be torn to pieces if the side of the groove against which it does so press were made at all uneven.

What l claim as my invention, and desire to secure by Letters Patent, is

L'A gun the lands of the riliing of which have a true spiral edge from breech to muzzle at the side which resists the straight movement of the sabot, and which are reduced on the other side at the breech, such reduction extend@ ing forward through a portion of their length,

' substantially as before set forth.

2. A gnu the lands of the riding` of which are reduced in width at the muzzle, said reduction extending back through a portion of their length, substantially as and for the purposes Set forth.

3. A gun with the lands reduced in Width at the breech end and at the muzzle thereof, substantially as and for the purposes set forth.

4.. A gun with one or more of the lands of the riding reduced in the middle portion ofthe length of the riiing to allow windage, substantially as and for the purposes set forth.

5. A gun with the lands reduced in width at r 5 the breech end of the gun and at the muzzle of the gun and reduced in the middle portion of the length ofthe riding to allow windage, substantially as and for the purposes set forth.

HUGH REILLY. Witnesses PHILLIPS ABBOTT, B. T. VETTERLEIN. 

